Bicarbonate Therapy and Intracellular Acidosis

1997 ◽  
Vol 93 (6) ◽  
pp. 593-598 ◽  
Author(s):  
D. J. A. Goldsmith ◽  
L. G. Forni ◽  
P. J. Hilton

1. The correction of metabolic acidosis with sodium bicarbonate remains controversial. Experiments in vitro have suggested possible deleterious effects after alkalinization of the extracellular fluid. Disequilibrium of carbon dioxide and bicarbonate across cell membranes after alkali administration, leading to the phenomenon of ‘paradoxical’ intracellular acidosis, has been held responsible for some of these adverse effects. 2. Changes in intracellular pH in suspensions of leucocytes from healthy volunteers were monitored using a fluorescent intracellular dye. The effect in vitro of increasing extracellular pH with sodium bicarbonate was studied at different sodium bicarbonate concentrations. Lactic acid and propionic acid were added to the extracellular buffer to mimic conditions of metabolic acidosis. 3. The addition of a large bolus of sodium bicarbonate caused intracellular acidification as has been observed previously. The extent of the intracellular acidosis was dependent on several factors, being most evident at higher starting intracellular pH. When sodium bicarbonate was added as a series of small boluses the reduction in intracellular pH was small. Under conditions of initial acidosis this was rapidly followed by intracellular alkalinization. 4. Although intracellular acidification occurs after addition of sodium bicarbonate to a suspension of human leucocytes in vitro, the effect is minimal when the conditions approximate those seen in clinical practice. We suggest that the observed small and transient lowering of intracellular pH is insufficient grounds in itself to abandon the use of sodium bicarbonate in human acidosis.

1989 ◽  
Vol 256 (5) ◽  
pp. H1316-H1321 ◽  
Author(s):  
J. I. Shapiro ◽  
M. Whalen ◽  
R. Kucera ◽  
N. Kindig ◽  
G. Filley ◽  
...  

Rats subjected to ammonium chloride-induced metabolic acidosis or respiratory acidosis caused by hypercapnia were given alkalinization therapy with either sodium bicarbonate or Carbicarb. Ammonium chloride induced dose-dependent systemic acidosis but did not affect intracellular brain pH. Hypercapnia caused dose-dependent systemic acidosis as well as decreases in intracellular brain pH. Sodium bicarbonate treatment resulted in systemic alkalinization and increases in arterial PCO2 in both acidosis models, but it caused intracellular brain acidification in rats with ammonium chloride acidosis. Carbicarb therapy resulted in systemic alkalinization without major changes in arterial PCO2 and intracellular brain alkalinization in both acidosis models. These data demonstrate that bicarbonate therapy of systemic acidosis may be associated with "paradoxical" intracellular brain acidosis, whereas Carbicarb causes both systemic and intracellular alkalinization under conditions of fixed ventilation.


2014 ◽  
Vol 120 (4) ◽  
pp. 926-934 ◽  
Author(s):  
Antoine Kimmoun ◽  
Nicolas Ducrocq ◽  
Nacira Sennoun ◽  
Khodr Issa ◽  
Charlène Strub ◽  
...  

Abstract Background: Lactic acidosis is associated with cardiovascular failure. Buffering with sodium bicarbonate is proposed in severe lactic acidosis. Bicarbonate induces carbon dioxide generation and hypocalcemia, both cardiovascular depressant factors. The authors thus investigated the cardiovascular and metabolic effects of an adapted sodium bicarbonate therapy, including prevention of carbon dioxide increase with hyperventilation and ionized calcium decrease with calcium administration. Methods: Lactic acidosis was induced by hemorrhagic shock. Twenty animals were randomized into five groups: (1) standard resuscitation with blood retransfusion and norepinephrine (2) adapted sodium bicarbonate therapy (3) nonadapted sodium bicarbonate therapy (4) standard resuscitation plus calcium administration (5) hyperventilation. Evaluation was focused in vivo on extracellular pH, on intracellular pH estimated by P31 nuclear magnetic resonance and on myocardial contractility by conductance catheter. Aortic rings and mesenteric arteries were isolated and mounted in a myograph, after which arterial contractility was measured. Results: All animals in the hyperventilation group died prematurely and were not included in the statistical analysis. When compared with sham rats, shock induced extracellular (median, 7.13; interquartile range, [0.10] vs. 7.30 [0.01]; P = 0.0007) and intracellular acidosis (7.26 [0.18] vs. 7.05 [0.13]; P = 0.0001), hyperlactatemia (7.30 [0.01] vs. 7.13 [0.10]; P = 0.0008), depressed myocardial elastance (2.87 [1.31] vs. 0.5 [0.53] mmHg/μl; P = 0.0001), and vascular hyporesponsiveness to vasoconstrictors. Compared with nonadapted therapy, adapted bicarbonate therapy normalized extracellular pH (7.03 [0.12] vs. 7.36 [0.04]; P < 0.05), increased intracellular pH to supraphysiological values, improved myocardial elastance (1.68 [0.41] vs. 0.72 [0.44] mmHg/μl; P < 0.05), and improved aortic and mesenteric vasoreactivity. Conclusions: A therapeutic strategy based on alkalinization with sodium bicarbonate along with hyperventilation and calcium administration increases pH and improves cardiovascular function.


2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
María M. Adeva-Andany ◽  
Carlos Fernández-Fernández ◽  
David Mouriño-Bayolo ◽  
Elvira Castro-Quintela ◽  
Alberto Domínguez-Montero

Metabolic acidosis occurs when a relative accumulation of plasma anions in excess of cations reduces plasma pH. Replacement of sodium bicarbonate to patients with sodium bicarbonate loss due to diarrhea or renal proximal tubular acidosis is useful, but there is no definite evidence that sodium bicarbonate administration to patients with acute metabolic acidosis, including diabetic ketoacidosis, lactic acidosis, septic shock, intraoperative metabolic acidosis, or cardiac arrest, is beneficial regarding clinical outcomes or mortality rate. Patients with advanced chronic kidney disease usually show metabolic acidosis due to increased unmeasured anions and hyperchloremia. It has been suggested that metabolic acidosis might have a negative impact on progression of kidney dysfunction and that sodium bicarbonate administration might attenuate this effect, but further evaluation is required to validate such a renoprotective strategy. Sodium bicarbonate is the predominant buffer used in dialysis fluids and patients on maintenance dialysis are subjected to a load of sodium bicarbonate during the sessions, suffering a transient metabolic alkalosis of variable severity. Side effects associated with sodium bicarbonate therapy include hypercapnia, hypokalemia, ionized hypocalcemia, and QTc interval prolongation. The potential impact of regular sodium bicarbonate therapy on worsening vascular calcifications in patients with chronic kidney disease has been insufficiently investigated.


2021 ◽  
Author(s):  
Tiehua Wang ◽  
Lingxian Yi ◽  
Hua Zhang ◽  
Tianhao Wang ◽  
Jingjing Xi ◽  
...  

Abstract Background: The role of sodium bicarbonate therapy (SBT) remains controversial. This study aimed to investigate whether hemodynamic status before SBT contributed to the heterogeneous outcomes associated with SBT in acute critically ill patients.Methods: We obtained data from patients with metabolic acidosis from the Medical Information Mart for Intensive Care (MIMIC)-III database. Propensity score matching (PSM) was applied to match the SBT group with the control group. Logistic regression and Cox regression were used to analyze a composite of newly “developed or exacerbated organ dysfunction” (d/eOD) within 7 days of ICU admission and 28-day mortality associated with SBT for metabolic acidosis.Results: A total of 1765 patients with metabolic acidosis were enrolled, and 332 pairs obtained by PSM were applied to the final analyses in the study. An increased incidence of newly d/eOD was observed in the SB group compared with the control group (54.8% vs 44.6%, p<0.01). Multivariable logistic regression indicated that the adjusted OR of SBT for this composite outcome was no longer significant [OR (95% CI): 1.39 (0.9, 1.85); p=0.164]. This effect of SBT did not change with the quintiles stratified by pH. Interestingly, SBT was associated with an increased risk of the composite of newly d/eOD in the subgroup of patients with worsening hemodynamics before SBT [adjusted OR (95% CI): 3.6 (1.84, 7.22), p< 0.001]. Moreover, the risk potential for this composite of outcomes was significantly increased in patients characterized by both worsening [adjusted OR (95% CI): 2.91 (1.54, 5.47), p< 0.001] and unchanged hemodynamics [adjusted OR (95% CI): 1.94 (1.01, 3.72), p=0.046) compared to patients with improved hemodynamics before SBT. Our study failed to demonstrate an association between SBT and 28-day mortality in acute critically ill patients with metabolic acidosis.Conclusions: Our findings suggested that SBT for metabolic acidosis was associated with an increased risk potential for subsequent d/eOD, while the hemodynamic status remained unstable during the acute phase of critical illness.


1963 ◽  
Vol 204 (6) ◽  
pp. 1048-1054 ◽  
Author(s):  
Ronald B. Miller ◽  
Ian Tyson ◽  
Arnold S. Relman

Intracellular pH of isolated rat diaphragm was measured with both a C14-DMO method and a tissue CO2 technique. The values for intracellular pH by each method, although slightly different, changed in parallel under most experimental conditions. Acute, severe potassium depletion in vitro had no detectable effect on intracellular pH, nor did prior depletion in vivo followed by incubation in a potassium-free bath. This was true whether or not the potassium-depleted muscle was exposed to normal or elevated extracellular levels of bicarbonate, and was unaffected by the presence of cationic amino acids in the bath. Acute repletion of previously potassium-depleted muscle resulted in a small rise in cell pH, but this was no greater than that produced by loading normal tissues with potassium. It is concluded that under the conditions of these experiments there is no evidence of intracellular acidosis in potassium-depleted skeletal muscle. Rat diaphragm can lose up to half its potassium content in vitro without detectable increase in hydrogen ion concentration.


1987 ◽  
Vol 252 (1) ◽  
pp. G109-G113
Author(s):  
R. M. Henderson ◽  
J. Graf ◽  
J. L. Boyer

Intracellular pH (pHi) was measured directly in isolated rat hepatocyte couplets using pH sensitive microelectrodes. The hepatocytes were maintained in a minimal salt buffer without added hormones or serum. Values of pHi (6.99 +/- 0.12, mean +/- SE) were close to their Nernst equilibria. After intracellular acidification with ammonium chloride, pH regulation was inhibited with 1 mM amiloride or by omission of external sodium, consistent with a Na-H exchange mechanism. Mean intracellular buffering power, in the nominal absence of carbon dioxide, was 34.1 +/- 11.4 mM. In the presence of external bicarbonate, amiloride or omission of sodium slowed, but did not completely inhibit recovery from acidification, indicating that additional pHi regulation mechanisms may operate in this preparation. These studies provide a direct measurement of pHi in hepatocyte couplets and indicate that Na-H exchange, together with a bicarbonate dependent system are important mechanisms for pHi regulation in this preparation.


1990 ◽  
Vol 259 (4) ◽  
pp. G564-G570 ◽  
Author(s):  
S. Arvidsson ◽  
K. Carter ◽  
A. Yanaka ◽  
S. Ito ◽  
W. Silen

The effects of intracellular acidosis induced by acidification of the basolateral (nutrient) perfusate on the structure and function of the oxynticopeptic cell were studied in in vitro frog gastric mucosa. Changing the pH of the unbuffered nutrient perfusate (UNB) from 7.2 to 3.5 acidified the oxynticopeptic cell with no change in potential difference (PD) or resistance (R). Intracellular pH (pHi), PD, and R were 7.05 +/- 0.01, 16 +/- 1 mV, 165 +/- 7 omega.cm2 before and 6.44 +/- 0.01, 16 +/- 2 mV, 170 +/- 9 omega.cm2 after nutrient acidification. Acid secretion (H+) increased from 0.86 +/- 0.07 to 1.88 +/- 0.18 mu eq.cm-2.h-1. Addition of forskolin to tissues perfused with nutrient pH (pHn) 3.5 decreased PD to 2 +/- 2 mV and further increased H+ to 3.07 +/- 0.19 mu eq.cm-2.h-1. By light and electron microscopy oxynticopeptic cells perfused with UNB, pHn 3.5, appeared normal. Oxynticopeptic cells in tissues pretreated with omeprazole and then exposed to UNB, pHn 3.5, had extensive morphological damage. On increasing the pH of the nutrient perfusate from 3.5 to 7.2 there was prompt recovery of pHi in untreated and forskolin-stimulated mucosae (pHi 6.87 +/- 0.06 and 6.85 +/- 0.04) but no recovery of pHi in tissues pretreated with omeprazole or cimetidine (pHi 6.26 +/- 0.04 and 6.44 +/- 0.06, n = 6, 30 min after reexposure to UNB, pHn 7.2). We conclude that in a secreting mucosa intracellular acidification of the oxynticopeptic cell to pHi 6.4 is associated with normal morphology, PD, R, and increased H+, and that intracellular acidosis is not de facto deleterious.


1995 ◽  
Vol 88 (4) ◽  
pp. 405-412 ◽  
Author(s):  
Alan Bevington ◽  
Dennis Brough ◽  
Frease E. Baker ◽  
Jane Hattersley ◽  
John Walls

1. During metabolic acidosis, significant fluxes of inorganic phosphate (Pi) may occur from cellular to extracellular fluid. In this study Pi was measured in erythrocytes of uraemic patients before and after haemodialysis and was related to their plasma pH (acidosis), plasma Pi (hyperphosphataemia) and cellular organic phosphate concentrations. 2. Before dialysis, the ratio of cellular to extracellular Pi concentration correlated inversely with plasma pH, increasing 2.5-fold as pH fell from 7.4 to 7.2. 3. An increase in cellular Pi similar to that seen in the patients was observed within 90 min of adding acid to normal erythrocytes in vitro. 4. The total Pi content of the cell suspension increased 25% on decreasing plasma pH from 7.4 to 7.2, largely as a result of generation of Pi from 2,3-bisphosphoglycerate in the cells. This was accompanied by net efflux of Pi into plasma. 5. In addition, the increase in the steady-state cellular Pi concentration on adding a constant extracellular Pi load was 50% greater at pH 7.2 than at 7.4, implying that alterations in the regulation of the transmembrane Pi gradient also contribute to the rise in cellular Pi observed at low pH. 6. At normal plasma Pi concentration (1 mM), glycolytic flux (lactate production) was inhibited by 20% when pH was lowered from 7.4 to 7.2. However, this inhibition was blocked when cellular Pi was increased by adding Pi to the plasma in vitro. 7. Metabolic acidosis is therefore a potent stimulus for Pi generation in erythrocytes, and this Pi may serve to stimulate glycolysis which is normally inhibited by low pH.


1994 ◽  
Vol 103 (5) ◽  
pp. 917-936 ◽  
Author(s):  
B A Watts ◽  
D W Good

The renal medullary thick ascending limb (MTAL) actively reabsorbs ammonium ions. To examine the effects of NH4+ transport on intracellular pH (pHi) and the mechanisms of apical membrane NH4+ transport, MTALs from rats were isolated and perfused in vitro with 25 mM HCO3(-)-buffered solutions (pH 7.4). pHi was monitored using the fluorescent dye BCECF. In the absence of NH4+, the mean pHi was 7.16. Luminal addition of 20 mM NH4+ caused a rapid intracellular acidification (dpHi/dt = 11.1 U/min) and reduced the steady state pHi to 6.67 (delta pHi = 0.5 U), indicating that apical NH4+ entry was more rapid than entry of NH3. Luminal furosemide (10(-4) M) reduced the initial rate of cell acidification by 70% and the fall in steady state pHi by 35%. The residual acidification observed with furosemide was inhibited by luminal barium (12 mM), indicating that apical NH4+ entry occurred via both furosemide (Na(+)-NH4(+)-2Cl- cotransport) and barium-sensitive pathways. The role of these pathways in NH4+ absorption was assessed under symmetric ammonium conditions. With 4 mM NH4+ in perfusate and bath, mean steady state pHi was 6.61 and net ammonium absorption was 12 pmol/min/mm. Addition of furosemide to the lumen abolished net ammonium absorption and caused pHi to increase abruptly (dpHi/dt = 0.8 U/min) to 7.0. Increasing luminal [K+] from 4 to 25 mM caused a similar, rapid cell alkalinization. The pronounced cell alkalinization observed with furosemide or increasing [K+] was not observed in the absence of NH4+. In symmetric 4 mM NH4+ solutions, addition of barium to the lumen caused a slow intracellular alkalinization and reduced net ammonium absorption only by 14%. Conclusions: (a) ammonium transport is a critical determinant of pHi in the MTAL, with NH4+ absorption markedly acidifying the cells and maneuvers that inhibit apical NH4+ uptake (furosemide or elevation of luminal [K+]) causing intracellular alkalinization; (b) most or all of transcellular ammonium absorption is mediated by apical membrane Na(+)-NH4(+)-2Cl- cotransport; (c) NH4+ also permeates a barium-sensitive apical membrane transport pathway (presumably apical membrane K+ channels) but this pathway does not contribute significantly to ammonium absorption under physiologic (symmetric ammonium) conditions.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Dimitrios Velissaris ◽  
Vasilios Karamouzos ◽  
Nikolaos Ktenopoulos ◽  
Charalampos Pierrakos ◽  
Menelaos Karanikolas

Introduction. Sepsis and its consequences such as metabolic acidosis are resulting in increased mortality. Although correction of metabolic acidosis with sodium bicarbonate seems a reasonable approach, there is ongoing debate regarding the role of bicarbonates as a therapeutic option.Methods. We conducted a PubMed literature search in order to identify published literature related to the effects of sodium bicarbonate treatment on metabolic acidosis due to sepsis. The search included all articles published in English in the last 35 years.Results. There is ongoing debate regarding the use of bicarbonates for the treatment of acidosis in sepsis, but there is a trend towards not using bicarbonate in sepsis patients with arterial blood gaspH>7.15.Conclusions. Routine use of bicarbonate for treatment of severe acidemia and lactic acidosis due to sepsis is subject of controversy, and current opinion does not favor routine use of bicarbonates. However, available evidence is inconclusive, and more studies are required to determine the potential benefit, if any, of bicarbonate therapy in the sepsis patient with acidosis.


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